1. Technical Field
The present invention relates to video display equipment such as a television receiver, a monitor, and more particularly, relates to an information display device for the video display equipment which displays information such as a character, a numeral and a symbol on a screen of the video display equipment.
2. Related Art
Generally, video display equipment such as monitors and television receivers are adapted to display desired information on their screens to inform users of current operation states. For example, when the volume and channel are adjusted in television receivers in accordance with the user's operation, information data such as the set volume, the previously set channel and the current channel are displayed on the screen. Similarly, when the horizontal and vertical sizes, horizontal and vertical positions, brightness and clearness levels are adjusted in monitors in accordance with the user's operation as disclosed, for example, in U.S. Pat. No. 5,457,473 for Image Display Apparatus issued to Arai et al., adjusted values are displayed on the screen to inform the user of current operational states.
Typical video display equipment includes an on-screen display (OSD) unit for displaying the desired information on the screen. Examples of contemporary video display equipments using OSD units are disclosed in U.S. Pat. No. 5,343,307 for On-Screen Display Apparatus issued to Mizuno et al., U.S. Pat. No. 5,486,842 for On-Screen Display Circuit Of The Interlaced Scanning Type issued to Kim, U.S. Pat. No. 5,493,340 for Circuit For Displaying Screen Control States Of A Monitor issued to Kim, and U.S. Pat. No. 5,627,564 for Graphic On-Screen Display Method issued to Yang. Conventional OSD unit generally includes a data memory for storing character data and a font memory for storing font data corresponding to the character data to be displayed on the screen of the video display equipment. Font memory can be random-access memory (RAM) or read-only-memory as disclosed, for example, in U.S. Pat. No. 4,763,118 for Graphic Display System For Personal Computer issued to Takai, U.S. Pat. No. 4,837,729 for Display Apparatus for Simultaneous Display Of Lines Of Characters Having Different Line Pitches issued to Funahashi, U.S. Pat. No. 4,954,979 for Personal Computer With Multiple Independent CRT Displays Of Ideographic And/Or ASCII Characters Having Loadable Font Memory For Storing Digital Representations Of Subset Or Special Characters issued to Eibner et al., U.S. Pat. No. 4,937,565 for Character Generator-Based Graphics Apparatus issued to Sawannukul, U.S. Pat. No. 5,231,383 for Videographics Display System issued to Diepstraten et al., and U.S. Pat. No. 5,311,213 for Display Control Device issued to Kosugi.
Font memory is required, however, to store font data of all information to be displayed on the screen. For example, in the case where 256 information data is to be displayed on the screen and font data of 12.times.10 bits is required for each piece of information, the font memory must have a 12.times.10.times.256-bit capacity. This memory requirement, as I have observed, is burdensome and cost prohibitive.